Is it possible to apply texture on every object in a image
Yes, if all of them have UV coordinates then you can make a material that uses UV coordinates to map the image. If not, you can use a material that uses generated coordinates (if in Cycles, maybe use Box mapping) and then you can mention that material in the over ride field in the Render Layers dialog.


edit: I had assumed you meant objects created, but now I realize you might be talking about a found picture - in this sense, you would have to model proxies for every object and use material(s) that share that image texture.